Immediate improvement of paretic hand function after epilepsy surgery in congenital hemiparesis

Introduction: Children with congenital hemiparesis and therapy refractory epilepsy are often good candidates for hemispherectomies. In some of these patients, the motor function of the paretic hand (contralateral to the resection) remains unchanged, which indicates a reorganization of this function into the contra-lesional hemisphere by the early brain lesion. An immediate improvement of paretic hand function has, however, not been reported yet.

A 17-year-old boy with congenital hemiparesis and therapy refractory epilepsy, both due to a large cortico-subcortical infarction in the vascular territory of the middle cerebral artery, underwent epilepsy surgery. Intraoperative electrical stimulation of the sensorimotor (Rolandic) cortex of the affected hemisphere elicited motor responses in the paretic hand, indicating preserved crossed motor projections from the affected hemisphere. A fronto-parietal resection was performed thereafter, during which the entire sensomotor cortex of the affected hemisphere was removed or disconnected. Surprisingly, the paretic hand showed an improved function with reduced spasticity even on the first postoperative day, which persists to date.

Discussion: This patient apparently possessed motor projections to the paretic hand both from the lesioned hemisphere (crossed) and from the contra-lesional hemisphere (uncrossed), which is not an infrequent constellation in congenital hemiparesis. The postoperative improvement indicates that the crossed projection had been dysfunctional, maybe by transmitting epileptic dysfunction to the paretic hand. Postoperatively, the paretic hand is now exclusively under ipsilateral control by the contra-lesional hemisphere-“undisturbed” by the epileptic hemisphere. Thus, the detection of crossed motor projections from the affected hemisphere does not necessarily predict motor deterioration after hemispherectomy or similar procedures.